Airport visual aid facilities are facilities disposed at an airport to provide visual guidance signals for pilots to operate takeoff, landing, and taxiing of an aircraft. Common facilities include aviation lights. Usually, there is a plurality of aviation lights at the airport. Each aviation light requires a monitor to control on/off of the light. Guidance and risk warning can be provided for a pilot by controlling on/off of the light using the monitor.
A visual aviation light control system usually includes a power supply, a constant current regulator configured to regulate a loop current, a cable, a plurality of aviation lights, a plurality of isolation transformers, a monitor (referred to as a slave monitor) corresponding to each aviation light, and a master monitor configured to send a communication signal to the slave monitor.
To implement control over the aviation lights, the power supply, the constant current regulator, and the plurality of isolation transformers are connected in series using the cable. The master monitor is connected to the constant current regulator in parallel, and each aviation light and a corresponding slave monitor are connected to a secondary output terminal of one isolation transformer. The master monitor sends, by loading a power line carrier signal onto the cable, a communication signal to each slave monitor, to perform communication. The slave monitor obtains the power line carrier signal from the secondary output terminal of the isolation transformer in order to control on/off of the aviation light based on the power line carrier signal.
In an existing visual aviation light control system, a power line carrier between a master monitor and a slave monitor needs to pass through an isolation transformer, and is subject to attenuation. In addition, a path for transmitting a power line carrier signal between the master monitor and each slave monitor is an entire series loop and has a relatively long communication distance. As a result, the power line carrier signal between the master monitor and the slave monitor is seriously attenuated, and communication is unreliable.